In today’s A Lab Aloft, International Space Station Chief Scientist Julie Robinson, Ph.D., discusses the top research results from space station science in 2015.

Now that utilization of the orbiting laboratory is in full swing, more and more advances in science are coming out of research conducted aboard the International Space Station than ever before. With close to 500 investigations on-going, the space station continues to be not only a test bed for research that will help us travel further into space, but also continues to provide results that benefit humanity back on Earth. You probably know that this year saw the start of the historic One Year Mission and Twins Study, which will provide critical data and understanding for future missions to deep space. It also marked the first time lettuce has been grown and consumed in space, and we celebrated 15 years of continuous human presence aboard the only microgravity laboratory in the universe. What you may not know are some of the top results that came out in the past year, based on research on the International Space Station. These are my personal top picks.

Hope Crystallizes

In microgravity, crystals grow more slowly, but the molecules have time to more perfectly align on the surface of the crystal which returns much better research data. Credits: NASA

Clinical trials of a new drug for treating Duchenne Muscular Dystrophy (DMD) called TAS-205 have begun sponsored by Taiho Pharmaceutical (see the entry in clinicaltrials.gov). This drug was developed using improved structures of key proteins that were crystallized on the ISS. The microgravity environment supported growth of larger, higher-quality crystals. This allowed scientists to design a drug to fit specifically into a location on the protein associated with DMD. Based on ground research in animals with a similar genetic disease, the research team estimates that the drug may be able to slow the progression of DMD, an incurable genetic disorder that affects the muscles primarily in young males, by half.

For me, starting clinical trials is a real milestone for this ISS research. There are so many things that can stop a science result from making it to a new drug, but once it makes it to clinical trials, data and not fundraising will have the greatest influence.

First genetic results investigate a link between folate and eye health in space

Damage to vision has become one of the top medical concerns of long-duration spaceflight, with increased pressure in the head due to fluid shifting in the body as a top suspect cause. A real puzzle has been why this only occurs in some astronauts, but not all. In 2015, scientists identified two polymorphisms (versions of genes that are slightly different in different people) present in astronauts who experienced vision impacts in space.. In the prestigious Journal of the of American Societies for Experimental Biology paper, researchers describe the polymorphisms are in genes that are part of a metabolic pathway called 1C that also uses B vitamins. In affected individuals, there could be a link between vitamin status and eye health

This was the first time that NASA has ever looked at genetic data from a group of astronauts. What really surprised me is that the One-Carbon Metabolism Pathway associated with folate and DNA synthesis could be correlated with what scientists have been viewing as a pressure disruption from fluid shifts in the brain. And the really surprising thing is that there are similarities between astronaut data and women who have infertility from polycystic ovarian syndrome. These kinds of surprises are the places where new advances come from, and I can’t wait to see the next piece of evidence in the puzzle.

Better weather warnings help reduce risks

Observation of Hurricane Joaquin taken by the Expedition 45 crew aboard the ISS.

Though the ISS-RapidScat has only been aboard the space station for a little more than a year, its weather observations have already made a difference in reducing risks for humans back on Earth. In 2015, data from the RapidScat instrument on the station improved tracking of hurricane strength prior to and during landfall, and enabled better storm warnings to reduce risk to shipping and coastal populations. RapidScat is the first near-global scientific Earth-observing climate instrument specifically designed and developed to operate from the exterior of the space station. The instrument measures near-surface ocean wind speed and direction, and provides data that is used to support weather and marine forecasting, including tracking storms and hurricanes.

Wind maps like these from ISS-RapidScat help enable better storm warnings to reduce risk to shipping and coastal populations. Credits: NASA

NOAA uses the RapidScat data in their hurricane forecasting. There may not be a NASA logo sitting alongside the NOAA logo. As a resident of Houston, I have a personal understanding of the risks of not preparing for a hurricane as well as the risks of evacuation. Good forecasts are critical to saving lives. I am really glad to know the ISS-Rapidscat instrument is doing its part to make those predictions more accurate.

Surprising results from the Constrained Vapor Bubble investigation

A heat pipe is a system for transferring heat away from a source using thermal transfer and phase change between liquid and gas. They are great options in space because they don’t have moving parts like pumps, and they are also used in electronic devices so they won’t have to have fans or pumps. Joel Plawsky of Rensselaer Polytechnic Institute: The Constrained Vapor Bubble experiment took a simplified heat pipe into space to measure its performance without the complexities of the bubbles rising due to gravity (buoyancy driven convection). Operation in the microgravity environment provided a number of surprises.One was rapid controlled boiling (they call this “explosive nucleation”!) in the shortest CVB module. Another was that the discovery normal capillary-driven flow of liquid from the cold to the hot end of heat pipe collided with a backward flow of liquid from the hot end toward the cold end due to Marangoni convection. The Marangoni flow also occurs on Earth but is very, very difficult to observe due to the action of gravity. I have to admit I learned a lot about heat pipes from reading this paper and then talking to some experts to better understand how they work. There will be more studies to come—but that collision is a source of inefficiency. This is an exciting and surprising result to me because once the physics are better understood, it can be applied to make smaller and more efficient heat pipes everywhere, including in this hot laptop I am using right now.

Julie A. Robinson, Ph.D., is NASA’s International Space Station Chief Scientist, representing all space station research and scientific disciplines. Robinson provides recommendations regarding research on the space station to NASA Headquarters. Her background is interdisciplinary in the physical and biological sciences. Robinson’s professional experience includes research activities in a variety of fields, such as virology, analytical chemistry, genetics, statistics, field biology, and remote sensing. She has authored more than 50 scientific publications and earned a Bachelor of Science in Chemistry and a Bachelor of Science in Biology from Utah State University, as well as a Doctor of Philosophy in Ecology, Evolution and Conservation Biology from the University of Nevada Reno.

Anyone over 40 who is interested in their heart health can relate to a study that began on the International Space Station last week. As we get older, our arteries stiffen and this causes an increase in blood pressure (hypertension) and elevates the risk for cardiovascular disease. In so many ways, the effects of space on the human body look a lot like ageing, and there is evidence that when some astronauts go to the ISS their arteries stiffen. Could the effect be similar to the effects of lack of physical activity on Earth?

On Jan. 7 and 8, Tim Peake performed the first Vascular Echo Ultrasound session and used the Portable Doppler for the first time on orbit as part of the Vascular Echo study. The study is led by the Canadian Space Agency and its PI, Dr. Richard Hughson has a long career of innovative studies on heart and vascular health in space. Dr. Hughson is also a great international collaborator. Scientists from Canada and France are collaborating on this study, and the US, Germany and the UK were involved in the operations. It will be interesting for scientists from around the world to better understand if the challenges to the human body from being in space have an effect on stiffening of the arteries.

In today’s A Lab Aloft, Graham Scott, Ph.D., completes his two-part series looking at the National Space Biomedical Research Institute’s (NSBRI’s) and NASA’s Twins Study that is conducting biomedical research on a pair of identical twin brothers, who are both astronauts.

As you may recall from part one of this blog, personalized medicine involves the application of many sophisticated molecular and bioinformatics techniques. At a high level, it means that when you visit your doctor(s), they examine you and determine the best drug or therapeutic intervention based on your individual health and biomolecular profile, rather than what usually works for the general population. This approach views you as distinct from any other patient, and as such you receive care based on your unique genome. By obtaining and analyzing your genome, doctors can detect and characterize your individual genetic variants – and prescribe precision or personalized treatments accordingly.

This strategy of using genetic profiling to inform individualized treatments has become quite mainstream in the best cancer hospitals and leading medical schools. NASA and the National Space Biomedical Research Institute (NSBRI) have the long-term goal of employing this personalized approach to mitigate the significant health risks that astronauts will face during deep space exploration missions. The Twins Study that involves the identical twin Kelly brothers, who happen to also be astronauts, is a pilot demonstration project that will collect and analyze integrated omics data – thereby laying the foundations for such a personalized or precision medicine approach.

Personalized medicine also applies to enabling future space exploration missions, such as an expedition to Mars, by making such a multi-year journey much safer. The crew will need to be highly self-sufficient or “autonomous” during that multi-year journey to and from the red planet. This includes sending each astronaut with the right drugs to effectively treat them as an individual, should they become ill. We want to also ensure that each crew member has tailored countermeasures available to them, to help them sleep or relax. Personalized medicine is a cutting edge methodology to make space exploration as safe as possible for astronauts. It’s a strategy that allows us to harness the full arsenal of health advances that we’re seeing in our leading medical institutions and universities today.

NASA’s & NSBRI’s initiative may motivate the next generation of scientists, physicians, engineers and astronauts as they watch how omics studies are implemented as a precursor to deploying personalized medicine in space. In addition, these types of studies will help educate as well as address some of the ethical and philosophical questions that arise with genetics-based care.

We are carefully considering ethical considerations surrounding integrated omics studies. Astronauts are high profile public figures, but a person’s genome is unique and extremely private. In the hands of an expert, a person’s genome can infer a person’s susceptibility to developing certain diseases over the course of their lifetime. As you can imagine, this is not the kind of information an individual wants to publically disclose. Genetic information can also lead to inferences regarding the current or future health status of other close family members. In this way the findings and implications of an integrated omics study, such as the Twins Study, are not limited to the individual(s) being studied. Add to these considerations an astronaut’s fear of being grounded and prevented from participation in future space exploration missions, due to medical findings, and it is evident that a number of sensitive topics arise with integrated omics studies that must be thoughtfully addressed.

NASA is examining how to handle omics data and privacy concerns from the perspective of medical ethics. The Twins Study helps the agency begin to grapple with these potentially difficult and complex issues, including how to archive this type of genetic information, “mine” it responsibly, and develop and implement policies. To protect against the misuse of personal genetic information, NASA has put a strict information barrier in place between the research team and the flight surgeons whom are tasked with providing medical treatment to astronauts. This type of impermeable confidential barrier protects research subjects, and is a practice that may help mainstream terrestrial medicine evolve in regards to how sensitive genetic information should be treated.

These considerations are very important, because many people worry about how their own genetic information could potentially impact their lives, jobs, ability to procure life insurance, and their families. NASA and NSBRI are thinking through all of these concerns as they relate to the astronauts, providing a benchmark for the medical, research, and legal communities to consider.

We are not all going to travel to Mars, of course, but in the near future we are all likely to experience or observe the application of individualized medicine here on Earth. The use of omics data will help doctors here on Earth customize treatments and optimize care to the general public. The Twins Study is breaking new ground in this area of personalized medicine, and how we apply the concept in space can provide an informative example for leading institutions as they continue to transition into an individualized care approach.

Graham B.I. Scott, Ph.D. (NSBRI)

Graham Scott, Ph.D., is the Chief Scientist and Institute Associate Director at the National Space Biomedical Research Institute (NSBRI), NASA’s biomedical research institute that was established in 1997 to work in partnership with the agency’s Human Research Program. A New Zealander by birth, Scott served as a Royal New Zealand Air Force pilot before obtaining a Ph.D. in astrochemistry. He came to the U.S. in 1997 where he worked for Nobel Laureate Robert F. Curl, Jr, Ph.D., at Rice University. Scott then went on to work on the Human Genome Project at Baylor College of Medicine, followed by a decade of leading R&D and marketing teams in corporate America, before being recruited back to Baylor to undertake his current leadership role with NSBRI.

In today’s A Lab Aloft, Graham Scott, Ph.D., kicks off a two-part series looking at the National Space Biomedical Research Institute’s (NSBRI’s) and NASA’s Twins Study that is conducting biomedical research on a pair of identical twin brothers, who are both astronauts.

Medical care and biomedical research are rapidly becoming personal—as underscored by President Obama’s recently announced Precision Medicine Initiative that considers patient’s individual variations in genes, environment and lifestyle as inputs to disease prevention and treatment. The President’s Precision Medicine Initiative has the goal of generating the scientific evidence needed to propel precision medicine into clinical practice. Individualized healthcare unleashes powerful 21st century molecular diagnostics that offer exciting new treatment options for patients and their families. Molecular diagnostics analyze biological markers such as genes, proteins and metabolites present in a person’s tissues, cells and biofluids (such as blood or urine), by applying techniques developed by molecular biologists to medical testing.

In an effort to address the age-old question of “nature versus nurture,” the NASA and the National Space Biomedical Research Institute (NSBRI) funded Twins Study is conducting biomedical research on the Kelly brothers—identical twin astronauts. This first of its kind integrated “astro-omics” study will lay the foundations for the eventual development of precision medicine-based countermeasures for astronauts that may contribute to future missions to Mars. Spaceflight challenges humans in new, unexpected and extreme ways, and people on and off the ground will undoubtedly benefit from the knowledge obtained as a result of this unique investigation.

The origins of this research are also personal. The twins themselves, Mark and Scott Kelly, raised the idea that they be studied before, during, and after Scott’s current one year mission aboard the International Space Station. Scott is one of two selected crew members who will spend a full 12 months on orbit, rather than the usual six months. Meanwhile his brother Mark, a retired astronaut, remains firmly on the ground.

The Twins Study dovetails seamlessly with the one-year mission, creating an opportunity to take a detailed look at Scott’s DNA, his complement of proteins, the ensemble of bacteria living in his gut, and the milieu of metabolites found in his bloodstream. We call this type of research—where we simultaneously look at many different biomolecular levels—an integrated omics study.

The term “omics” is relatively new. In 2003 the first “finished” human genome, which detailed the genetic make-up or blueprint of a person, became broadly available to the scientific community. This led to an observation of how genes are copied or “transcribed” ahead of ultimately being synthesized into proteins, which we refer to as the transcriptome. This work was quickly followed by efforts to study the proteome, cataloging the thousands of proteins that are circulating at any given time in our blood or performing signaling within our cells. More recently we have characterized the microbiome, which refers to the community of microorganisms living within our gut and on our skin. We also are studying the epigenome, which involves investigating reversible chemical changes that occur dynamically within our DNA and the histone proteins that “package” our DNA as a result of environmental stressors. The number of “omes” that we can examine seems to continually increase and the term “omics” is an umbrella term to cover these areas of molecular research as a newly emerged category of biomedical study.

The opportunity to observe Scott (in space) and Mark (on the ground) at a fundamental biomolecular level is unique because they are identical twin brother astronauts. Around the turn of the 21st century we would have stated that they were genetically the same. Actually, it turns out that identical twins are not 100 percent identical. To a first order of approximation their DNA sequence is matched, but there are actually some small underlying genetic differences. Moreover, the biomolecules that are generated or “expressed” at the RNA, protein, and metabolite levels are quite different. This is due to the responses of each twin to the environment that they encounter at any given moment, as well as the experiences that have accumulated throughout their lifetimes.

We plan to look at both Mark and Scott’s molecular profiles at a fine, granular-level to see what is occurring with their genomes, transcriptomes, proteomes, metabolomes, etc. in space, relative to on the ground. Mark provides about as ideal of a control subject as one could imagine, because he is so close genetically to Scott. Starting in late 2014 we have been collecting biofluids and obtaining baseline measurements from Scott and Mark for the study. We will continue to collect samples from both twins following Scott’s return to Earth in early 2016.

An image of NASA astronaut Scott Kelly after arriving aboard the ISS to begin his year-long stay in space. (NASA)

What we may see with Scott, based on experiments previously performed using animal research models, are different RNA expression levels for certain genes, relative to what we typically observe on the ground. We can also perform a comparison of Scott’s RNA expression profile to that of his brother, Mark. For instance, during his mission Scott will experience approximately 20 times higher levels of radiation than Mark. This is because the combined effect of our planet’s protective atmosphere and strong magnetic field protects Earth-bound humans.

The impact that space radiation has on a person’s DNA is one of the things we’re interested in learning more about. We will study how rapidly the ends of the chromosomes or “telomeres” shorten in response to the effects of radiation and other stressors that are inherent to the space environment. This research on telomeres will provide follow-up data to the chromosomal damage published in 2008 by Dr. Francis Cucinotta and colleagues in Radiation Research.

A better understanding of the impact of space radiation at the molecular level may ultimately benefit cancer patients who undergo proton radiation as part of their treatment regimen. Up until the 21st century, cancer patients received radiation treatments that were quite different from what astronauts are bombarded with in space. Now many leading cancer hospitals are using proton therapy and some are even beginning to employ carbon ions to fight cancer. This “particle therapy” is similar to the heavy particle component of space radiation, though with varied rates and doses.

This higher radiation exposure Scott will experience in space may reveal biomolecular impacts in ways that could lead to new findings. The twins close genetics make them ideal study subjects for attempting to tease out the role of environmental effects in disease development, versus the inherent genetic makeup of a person.

We factored into the studies that Mark was an astronaut up until 2012, meaning he also spent a significant amount of time in space. Mark has spent 54 days in space, while Scott will accumulate 540 days on orbit by the end of his one-year mission—ten times as many days as his brother. Both of the brothers’ biomolecular profiles have almost certainly been impacted by their previous experience in space. Scott will of course encounter a new set of stressors, now that he is once again aboard the ISS.

Astronaut Mark Kelly, STS-124 commander, looking through the Earth observation window in the Japanese Experiment Module of the ISS during his 2008 mission. (NASA)

As with many scientific projects, the Twins Study is likely to raise more questions than answers. That said, we hope to have many tantalizing leads and interesting pieces of data to follow up on with more integrated omics research on larger numbers of astronauts.

To baseline the biomolecular profiles of both Scott and Mark, we obtained and safely stored blood, urine, saliva, and other biofluid samples. We also are performing a longitudinal study on Scott, by collecting samples while he was on Earth prior to launch, then following him throughout his space mission and again periodically for many months after his return. The same goes for Mark; we will perform a similar longitudinal study on him. For both twin astronaut brothers we will track them over time, specifically for several years. In fact we will be looking at Scott’s telomeres, as far out as 720 days after his landing in March 2016.

The results of this study won’t just impact the twins, but actually will have a lot to do with the rest of us living here on Earth. One of the things you may have noticed if you saw the President’s State of the Union speech was that Scott Kelly was in the First Lady‘s boxed seating area. During his speech President Obama specifically mentioned the one year mission and cited the importance of the area of personalized or precision medicine that is rapidly emerging as a powerful new set of techniques within biomedical research and clinical practice.

NASA astronaut Scott Kelly stands as he is recognized by President Barack Obama, while First Lady Michelle Obama (lower left corner) and other guests applaud. The President recognized Kelly during the State of the Union address on Capitol Hill in Washington D.C. on Jan. 20, 2015. (NASA/Bill Ingalls)

In part two of this blog posting, I will share with you the ethics and impacts of personalized medicine in space and on the ground.

Graham B.I. Scott, Ph.D. (NSBRI)

Graham Scott, Ph.D., is the Chief Scientist and Institute Associate Director at the National Space Biomedical Research Institute (NSBRI), NASA’s biomedical research institute that was established in 1997 to work in partnership with the agency’s Human Research Program. A New Zealander by birth, Scott served as a Royal New Zealand Air Force pilot before obtaining a Ph.D. in astrochemistry. He came to the U.S. in 1997 where he worked for Nobel Laureate Robert F. Curl, Jr, Ph.D., at Rice University. Scott then went on to work on the Human Genome Project at Baylor College of Medicine, followed by a decade of leading R&D and marketing teams in corporate America, before being recruited back to Baylor to undertake his current leadership role with NSBRI.

In today’s A Lab Aloft, Jean Sibonga, Ph.D., explains what’s next for microgravity bone research aboard the International Space Station. Using what we’ve learned in the last 50 years, investigations in orbit will help scientists pinpoint the impacts of countermeasures and refine treatments.

Boning Up on Skeletons in Space

All research begins with a question. In my case, two of them. My first question came from research I was doing during my postdoctoral study at the Harvard School of Dental Medicine working with oral biologists and orthodontists. Impressed with how an orthodontist can practically move teeth from one end of your mouth to another — I wondered about what told the cells to break down the bone at the front end of the tooth and then to fill in the cavity left by the tooth’s movement. What kind of chemical communication was happening to make this possible?

My second question came years later from former NASA administrator Michael Griffin during a visit to my directorate at Johnson Space Center. Griffin asked: “How can we make those bone cells stop what they are doing up in space?” He was referring to the real concern of accelerated bone loss for humans living in microgravity. He wanted to know if it were possible to stop the cells from breaking down bone.

Both questions about cell communication are fundamental to my research into bone strength and how it changes under certain circumstances, such as with aging or in microgravity. The answers are pivotal for long duration living in space, whether aboard the International Space Station or future missions. We’re trying to understand if space disrupts the communication between cells, whether this miscommunication is responsible for reducing the strength of bone and whether we can prevent this decline in strength by overriding this perturbed cellular communication.

You may have read about the findings from the first 50 years of bone research in space, compiled by my colleague Scott M. Smith, Ph.D., and his team. With Smith’s biochemical data we can get an idea of how cells are responding to the spaceflight environment—which cells are stimulated, which are suppressed or un-responsive. More importantly, we can try to figure out why this is happening—that is, are the signals that turn cells on or off not being produced or not being received? Pharmaceutical companies, for example, are particularly interested in this topic. The answer may help them develop medications for patient use on Earth. So, by refining our understanding of how current countermeasures work in space, at the cellular level, we might advance treatments for future space explorers, as well as Earth dwellers.

My research is an extension of Smith’s results. So far, our research suggests to us that the right combination of nutrition and specific types of exercise—can reduce the loss of bone mass in astronauts. What we still need to understand is whether the bones protected by the combined effects of diet and resistive exercise in space are as strong as they were before spaceflight.

My training in bone research was in histomorphometry; simply, it means that I measured bone tissue. I measured the amount of newly-formed tissue, I counted the number of cells, I calculated the rates of bone formation, I measured cellular activity. So while biochemistry helps researchers surmise why and how changes in a bone’s mass are occurring in microgravity, bone histomorphometry helps us understand the cellular activity that change bone tissue. The result of these changes—by different cells, on different surfaces—can end up reshaping the structure of bone.

Since the bone structure is a contributor to bone strength, I think it’s really important to understand how bone strength changes with spaceflight—not just how bone mass or bone cells change. After all, NASA research tries to solve potential problems in space by asking: Are astronaut’s bones strong enough to do the operations of a mission without fracturing? Will exposure to spaceflight cause fractures to occur earlier in an aging astronaut after he/she returns to Earth?

Research that describes how living in space changes bone cell signaling, bone mineral and bone structure helps us to understand how space may be changing the strength of bone. But, these research tools require looking at bone tissue extracted from animals or in biopsies from test subjects—not a very attractive test to spin-off for an Earth-based doctor.

So, in Earth-based medicine, bone clinicians use an x-ray-based technology to measure the amount of bone minerals in an image of bone, without having to remove any bone tissue from the body. But those measurements are no longer sufficient for understanding whether or not a bone will fracture. A previous flight study used a research technology called QCT to measure bone mineral in different astronauts’ hip bones before and after spaceflight. The study then used a computational tool that engineers developed to test the integrity of complex structures, like bridges or cars. This tool estimates the force of the load that would cause the hip to fracture by applying a “virtual” mechanical load to the computerized model of the hip until the structure “fails.” We are hoping to use these estimates to figure out which tasks performed by an astronaut could lead to a hip fracture.

My background in animal studies tells me that different countermeasures affect different types of bone cells in different locations of the hip. When countermeasures affect the very dense cortical bone shell differently from the spongy, more porous trabecular bone on the inside, then the overall structure of bone changes and the strength of the bone may change as a result. I like to remind people that you can’t “feel” when your bones are weakened. If we could compare hip bone strength with the loads of physical activity, we might be able to detect when an astronaut might overload his or her bones, even after return to Earth.

This is why I proposed a study called Hip QCT, which is building on results of multiple flight studies. It’s like a jigsaw puzzle. With biochemical tests, we can monitor the hormones that induce the production of protein signals, the signals that stimulate cellular activity, and the by-products that reflect the formation and the degradation of bone tissue. I hypothesized that Hip QCT can capture the difference between mechanical countermeasures, such as exercise, and biochemical countermeasures, like nutrition or pharmaceutical agents, because of its ability to detect changes in bone structure. In the end, we want to describe how countermeasures during spaceflight change the strength of the hip by changing the structure of hip bone.

There’s a problem with QCT as a test, however, as there is an issue with greater radiation exposure. One hip scan, for example, amounts to two to six days on the space station, depending on the age and sex of the astronaut. We’re trying to demonstrate the value of collecting QCT data and estimating hip strength. Someday we hope to detect the effects of spaceflight in astronauts on the connectivity of trabecular bone as observed in our mouse studies. We are investigating some emerging technologies which do not require any radiation. With these collective measures, we are hoping to prevent fractures by estimating which physical activities may cause bones to be overloaded during a mission or even after return to Earth.

Because we have an aggressive schedule for decision-making, NASA puts innovative approaches on a fast track for application. If NASA can clearly demonstrate the benefits of these innovations to protect astronaut health and performance, then the translation of these novel predictive capabilities may enhance the earlier diagnosis of osteoporosis in people here on Earth.

This was really brought home at last year’s meeting of the American Society for Bone and Mineral Research where I hosted a workshop. It was standing room only! Everything we learn about bone loss and rebuilding in space can also provide insights to the numerous scientists studying osteoporosis and its treatment on Earth.

In order to monitor changes in skeletal health that could lead to fracture, we need to leverage new and innovative ways of evaluating changes to bone tissue and the impact on bone strength. There’s a whole new generation of technologies and scientists to look into these questions. I am excited to see what we discover as we work together for better bones!

Jean Sibonga, Ph.D., lead scientist in the bonediscipline of bone research for the Human Research Program at NASA’s Johnson Space Center in Houston, TX (NASA)

Jean Sibonga, Ph.D. is the lead for bone discipline in the Human Research Program at NASA’s Johnson Space Center in Houston. Sibonga received her B.S. in Chemistry and English from the University of Puget Sound in Tacoma, Washington. She later earned her Ph.D. in Biochemistry from Loma Linda University, California. Sibonga has more than 30 years of research experience in bone cell biology & physiology at such institutions as the Jerry L. Pettis VAMC, Loma Linda, CA; NASA Ames Research Center; Harvard School of Dental Medicine; and the Mayo Clinic, Rochester, MN.

The latest in astro-chic fashion aboard the International Space Station is sure to generate a lot of buzz – among scientists, at least. Where else can you get away with wearing rubber suction pants? While these pants look a little unusual, they may help us understand a potentially serious vision problem that affects some astronauts on long duration spaceflights.

The human body is roughly 70% fluids, which includes blood, lymph, and water contained within and around cells. On Earth, our cardiovascular system keeps those fluids distributed throughout our body despite the pull of gravity. During spaceflight, body fluids accumulate in the upper body, causing a noticeable puffiness in astronauts’ faces. This redistribution of fluids may be contributing to the aforementioned vision impairment.

The Russian Chibis suit is designed to counteract the tendency for fluids to pool in the upper body by applying lower body negative pressure (LBNP). Chibis works like a household vacuum cleaner to suck astronauts into the pants, load the bottoms of their feet, and expand veins and tissues of the lower body. By sucking blood and other body fluids back to the lower body, swelling in the face and elevated pressure in heads of astronauts may be avoided.

During the one-year mission recently embarked upon by American Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko, a new investigation called Fluid Shifts seeks to test the relationship between the head-ward fluid shift and a pattern NASA calls visual impairment and intracranial pressure syndrome, or VIIP. VIIP involves changes in vision, the structure of the eyes and indirect signs of increased pressure in the brain. More than half of American astronauts have experienced VIIP symptoms during long spaceflights.

A unique aspect of the Fluid Shifts investigation is the use of the Russian Chibis suit, namely LBNP, during cardiovascular and VIIP-related physiological measurements. Precursors of LBNP actually include the ancient practices of bloodletting and cupping to alter blood volume and pressure in the sick. The first true use of LBNP was in the early 1950s, and it was widely used as a research tool to study the cardiovascular system in the 1960s. The Chibis suit was first used in spaceflight during the Salyut space station missions and has been used regularly late in missions as part of the cosmonauts’ health program to prepare them for return to Earth.

Exercise devices presently aboard ISS such as the cycle ergometer and treadmill provide a cardiovascular workout, but they are not designed to move blood and body fluids back toward the feet. LBNP stresses the cardiovascular and musculoskeletal systems in a way that is similar to standing and exercising on Earth. In a way, LBNP is an artificial gravity device.

In fact, the Fluid Shifts investigation may result in design of future space exploration exercise devices that simulate gravity and shift fluid to the lower body. Such a device may provide an integrative system for protecting astronauts across multiple physiologic systems prior to incorporation of more advanced concepts of artificial gravity such as a rotating spacecraft or a centrifuge.

The Fluid Shifts investigation has Earth benefits for health applications as well. Results may improve our understanding of how blood pressure in the brain affects eye shape and vision which could also benefit people confined to long-term bed rest, or suffering from disease states that increase swelling and pressure in the brain.

By now, you are no doubt wondering where you can get your own pair of rubber suction pants. You’re in luck! By using suction in exercise equipment on the ground, athletes can be trained at higher weight-bearing levels to improve their performance. Also, using positive pressure in a lower body chamber, elderly patients and people with leg injuries can be brought back to normal daily activities and “peak performance” earlier than possible with present modes of rehabilitation.

The Clinical Orthopaedic Lab at the University of California, San Diego has been involved in spaceflight cardiovascular, bone and muscle research for over 30 years; and we are particularly excited to be a part of the international team of investigators involved in the Fluid Shifts investigation. While unlikely to start a new fashion trend, we look forward to sharing the important results from the rubber vacuum pants that suck.

Alan Hargens, Ph.D. Credit: Alan Hargens, Ph.D.

Alan Hargens PhD., previously served as Chief of the Space Physiology Branch and Space Station Project Scientist at NASA Ames Research Center (1987-2000) and Consulting Professor of Human Biology at Stanford University (1988-2000). His recent research concerns gravity effects on the cardiovascular and musculoskeletal systems of humans and animals.

European Space Agency (ESA) astronaut Samantha Cristoforetti – dressed in a Star Trek Voyager uniform – takes a sip of espresso from the new Capillary Beverage investigation, also known as Space Cup while looking out of the Cupola window. Credits: NASA

You may have heard the “caffeine buzz” around the Internet about the ISSpresso machine that recently launched to the International Space Station. It would be out of this world indeed to have a cup to go along with it. So we designed, fabricated, tested, and flight qualified one. In fact six such cups are now on the space station and ready for action. With real science backing the design, our microgravity coffee cup will do more than lift espresso to astronauts’ lips — it will also provide data on the passive movement of complex fluids as part of the Capillary Beverage investigation. The results will confirm and direct math models that help engineers exploit capillary fluid physics (capillary fluidics) to control how liquids move by designing containers specific to the task at hand. Whether getting the last drop of fuel for a rocket engine or delivering the perfect dose of medication to a patient, there are real Earth benefits behind the brew.

In 2008, astronauts aboard the International Space Station demonstrated the pouch method of drinking yesterday’s coffee and today’s coffee, while the Space Cup will serve the coffee of tomorrow — providing real science for fluid physics research. In the front, left to right, crew members Michael Finke and Chris Ferguson, with Eric Boe and Donald Pettit in the back. (NASA)

On Earth, gravity is responsible for making bubbles rise and liquids fall. Such mechanisms vanish in the weightless environment of orbiting spacecraft. In fact, in microgravity there is no concept notion of floating or sinking, or up or down. Other forces such as surface tension that are normally overwhelmed by gravity on Earth rise to dominate liquid behavior.

In a spacecraft, if the effects of surface tension are not understood, liquids (e.g., water, fuel) can be just about anywhere in the container that holds them. Similarly, the gas (e.g., oxygen, nitrogen) in such containers can freely range, too. You’re in for a challenge if you want to find where these fluids are and use them. Even if you just want to drink them. This is why in space you’ll only see astronauts drinking from bags with straws so that they can completely collapse the bag to assure the liquids come out. From a practical safety perspective, the bags also provide a level of containment.

When my laboratory heard of ESA astronaut Samantha Cristoforetti and the Italian Space Agency’s espresso machine investigation (ISSpresso) going to space, it got us thinking about that beautifully complex drink and how it would behave differently — especially whether the coffee would develop a crema or not. Currently, we don’t believe so because the bubbles that form during the espresso brew process won’t naturally rise to the surface due to absence of buoyancy in the microgravity environment. Other weaker forces often masked by gravity are present and will likely play an unearthly role in what happens, making the espresso fun to observe. It will be a different kind of fun altogether to get real science out of the process at the same time.

In a normal cup of espresso, carbon dioxide bubbles release and collect to form a crema. Some of the bubbles adhere to the walls of the cup, while the remainder rise and stratify due to their size in layers we refer to as foam. Steam rises above the surface of the crema in part condensing in an advancing front on the inside surfaces of the cup. The cup cools by natural convection and the aromatics waft at rates determined by buoyancy. These processes are completely induced by gravity!

When the influence of gravity is greatly reduced, as it is aboard orbiting spacecraft, not much of this stuff is going to happen. This will be unusual for the astronauts. Even the smell of the coffee diffusing through the crema is driven by natural convection currents in the air, which are absent in the microgravity environment. So the simple, every day fluid physics taking place in your daily coffee are highly dependent on gravity. From taste to smell, we anticipate what may even be a disappointing cup of coffee in space. But only the astronauts will know, and we will have to take their word for it in the hopes of one day trying this for ourselves.

Touching your lips to the rim of the Space Cup establishes a capillary connection allowing the drinker access to the entire contents. Sip-by-sip or in one big gulp, the cup’s contents may be imbibed somewhat normally in space, as on Earth. (A. Wollman, IRPI)

You can imagine how many variables are at play for the drinking experience from a human factors perspective, but gravity influences many of these, too. Sinus drainage, saliva migration, time aloft, and others are reasonable microgravity-related parameters affecting one’s response to the drinking experience in space. We designed the Space Cup with the central objective of delivering the liquid passively to the lip of the cup. To do this we exploit surface tension, wetting conditions, and the special geometry of the cup itself. We have yet to learn the human-cup interaction in microgravity. The cup design forces the drinker’s nose directly over the fluid contents. But since the aromatics do not rise, one might expect a rather concentrated dose upon the first whiff. Maybe this won’t be a big deal since astronauts report a reduced sense of smell while in space, due to somewhat clogged sinuses. This is presumably due to the headward fluid redistribution that occurs in spaceflight.

We were highly motivated to make the cup transparent so we could observe all of the fluid physics going on in the process. It may sound nerdy, but that’s what we do—we study microgravity fluid physics in hopes of designing more reliable fluid systems for future spacecraft, and more effective fluid systems for applications on Earth.

Touching your lips to the rim of the cup establishes a capillary connection, almost like the wicking of water through a paper towel, allowing the drinker access to the entire contents. My colleagues and I have been doing research aboard station for more than 10 years. During the course of hundreds and hundreds of experiments, we’ve been developing the mathematical predictive tools and computational tools for such passive capillary fluidic processes. Now we are in a place to develop designs for systems in space — systems with promises of high reliability because they perform their function passively, without moving parts. Examples include things like urine treatment and processing, and systems to close the water cycle helping to enable truly long duration crewed space exploration. These same tools also help us with fuel systems, cooling systems, water processing equipment for plant and animal habitats, and much more.

Perfecting these systems can also help us prevent disasters in orbit or on long-duration missions such as the journey to Mars. For example, the primary oxygen supply systems on many spacecraft use electrolysis. If the system gets a single air bubble lodged within its tubing, it can shut down until the bubble is found and removed. To get a sense of working with these types of systems in space, you need an understanding of capillary phenomena from studies, believe it or not, like Capillary Beverage.

The Space Cup’s specific design uses known geometry, gathered in prior International Space Station research, to direct fluids to the lip of the user. (Credit: M. Meyer, IRPI)

While fun, this study has plenty of design research behind it. Many of the aspects of our fluid physics research in microgravity are present in this simple cup demonstration — the effects of wetting, the effects of geometry, and the effects of fluid properties, especially surface tension. The results could provide information useful to engineers who design fuel tanks for commercial satellites, for instance. If you can find all your fuel, you can save costs and maximize the mission duration.

With this cup we can also study complex fluids that we have not previously addressed. For example, just adding sugar or milk to tea is expected to radically change the performance of the process of how the fluids move. We’ll approach this systematically aboard the space station. We’re starting off with water, then clear juice, then tea, tea with sugar, etc., including complex drinks like cocoa, a chocolate breakfast drink, and even a peach-mango smoothie. Undissolved solids, dissolved gasses, foams, free bubbles, surfactants, varying viscosities, temperature effects and more — all in little transparent 3D printed cups used by astronauts to drink on the space station. This progression from simple to complex beverages will give us a wealth of data — data which we aim to apply not just in space, but on Earth, too.

The astronaut(s) will set up the experiment near the galley, position the cup, camera, and lighting for orthogonal views (views at right angles), and a variety of experiments will be performed using the HD video as our quantitative data source. For example, when the astronaut fills the cup, the filing process is research. When the astronaut drains the cup, the draining is research. The static and dynamic interface shapes tell us everything we need to know, from wetting conditions to stability, to visco-capillary interaction. This is the exciting part for us! We see the profile of the interface, we watch particles and bubbles as flow tracers, we get velocities and volumetric drain rates, and all as functions of what the astronaut is doing — enjoying a cup of coffee! Astronaut Kjell Lindgren is planning to take up plenty of his own espresso during Expeditions 44/45. We have plenty to look forward to.

International Space Station Expedition 44/45 crew members Kjell Lindgren and Kimiya Yui enjoying food tasting at NASA’s Habitability and Environmental Factors Office in Houston. Lindgren plans to take his own espresso grounds with him into orbit to enjoy as part of the Capillary Beverage study. (NASA/Bill Stafford)

With this cup, most everything is taken care of passively by the shape of the cup. There isn’t a straight line in it. There are no moving parts. Wouldn’t it be nice if all the fluid systems on spacecraft worked like that? We know it would result in less worry on the ground. The simpler things are, the more robust their function and the less time is needed for maintenance.

What we are learning here is not just for space. All the design tools we are developing are applicable to small fluidic systems on Earth, too. For example, portable point-of-care medical diagnostic devices exploit capillary flow to passively move a very small sample of blood to any variety of regions on a testing chip. That makes it possible to diagnose infectious diseases in places where there is no power or where power is unreliable. It also reduces the time between sample collection and diagnosis and, therefore, initiation of treatment. We will report more on this connection in the future.

The next time you brew a cup of your favorite coffee, imagine what it might be like to take a sip from the Capillary Beverage cup aboard the International Space Station while watching the Earth go by. Then consider the fluids research off the Earth, that can make a difference right here on the Earth.

Mark Weislogel, Ph.D. (Portland State University)

Mark Weislogel, Ph.D., is senior scientist and vice president of IRPI LLC and professor Mechanical Engineering at Portland State University. He was founded in microgravity fluid physics while employed at NASA’s Glenn Research Center. Whether in the private sector or academia, Weislogel has since continued to make extensive use of NASA ground-based low-gravity facilities and has completed investigations aboard space shuttles, the Russian Mir Space Station, and the International Space Station. He led the design of the Dryden Drop Tower, which has conducted over 4,000 drop tests and continue at a rate of over 1,000/year. Current efforts are directed to research, development, and delivery of advanced fluid systems for spacecraft.

Today’s A Lab Aloft was posted by Ellen Stofan and Julie Robinson on April 17, 2015.

The International Space Station is a unique laboratory for performing investigations that affect human health both in space and on Earth. Since its assembly, the space station has supported research that is providing a better understanding of certain aspects of both fundamental and applied human health, such as the mechanisms causing aging and disease. Several biological and human physiological investigations have yielded important results, including improved understanding of bone loss and rebuilding, and development of new medical technologies that have impacted lives right here on Earth.

From studying the behavior of cells to developing potential improvements in clinical settings, a variety of health research arrived at the space station today aboard the sixth SpaceX contracted resupply mission. The Dragon spacecraft delivered research equipment for biology, biotechnology, human research, as well as additional research and supplies to the station. These new and ongoing investigations continue to assist researchers in pursuing scientific and medical knowledge not possible under the weight of gravity on Earth.

A SpaceX Falcon 9 rocket lifts off from Space Launch Complex 40 at Cape Canaveral Air Force Station carrying the Dragon resupply spacecraft on the sixth commercial resupply services mission to the International Space Station. Liftoff was at 4:10 p.m. EDT on April 14. (NASA/Tony Gray)

NASA astronaut Scott Kelly and his identical twin brother Mark will participate in a series of human health studies as part of the recently begun One-Year Mission aboard the space station. The data collected comparing the twins, Scott on the space station, and Mark living on Earth, will enable researchers to determine how cognitive function, metabolic profiles, gastrointestinal microbiota, immune system and genetic sequences are affected by different factors attributable to the environmental stress of spaceflight. Results could potentially be used as the first steps to understand how to help develop new treatments and preventive measures for health issues on Earth.

Another investigation will study how and why some astronauts experience eye changes that can affect their vision during missions aboard the station. There are several factors that may cause this problem during spaceflight. This research will improve scientists’ understanding of this phenomenon and how changes in the brain and eye shape affects vision. It could also help people on Earth suffering from conditions that increase swelling and pressure in the brain.

NASA astronaut Michael Hopkins and European Space Agency astronaut Luca Parmitano perform ultrasound eye imaging as part of the Fluid Shifts investigation during Expedition 37 on the International Space Station. (NASA)

Studying cells in space is another important area of health research on the station. Research in microgravity provides an important novel tool to better understand the mechanisms that cause cellular functions such as cell division, gene expression and shape. Looking at cells in space provides unique insights, because in the absence of Earth’s gravity, cells grow with a similar structure as they do in the body. Scientists can use this knowledge to improve diagnosis and therapies.

A type of bone cell, called osteocytes, will arrive at the space station on today’s cargo delivery as part of a project funded under the Biomedical Research on the International Space Station (BioMed-ISS). This initiative is a collaborative effort among the National Institutes of Health, the ISS National Laboratory and NASA. The investigation team, led by Dr. Paola Divieti Pajevic, Assistant Professor at Boston University and the Director of the bone cell core at Massachusetts General Hospital, will analyze the effects of microgravity on the function of osteocytes. The study will provide better understanding of the mechanisms behind bone disorders on Earth, such as osteoporosis.

The three colorful bioreactors where mouse bone cells grow within a 3D material for the Osteo-4 investigation aboard the International Space Station. (Divieti Pajevic Laboratory)

Additional investigations also may yield results that can potentially improve patient health in clinical settings on Earth. Scientists may be able to develop methods for combating hospital-acquired infections, a chronic problem in clinical settings, by researching bacterial growth in a microgravity environment. Moreover, by studying protein crystallization in space, scientists may be able to improve crystallization technology that can change the way drugs are used for treating various human diseases.

The programs outlined here illustrate only a fraction of the space station’s potential as a groundbreaking scientific research facility. The International Space Station National Laboratory, as designated by the 2005 NASA Authorization Act, is a unique scientific platform that continues to enable researchers to put their talents to work on innovative experiments that could not be done anywhere else. Use of the space station’s singular capabilities as a permanent microgravity platform with exposure to the space environment is improving life on Earth; fostering relationships among NASA, other federal entities, and the private sector; and advancing science, technology, engineering and mathematics (STEM) education.

We may not know yet what will be the most important discovery gained from this orbiting laboratory, but we already are doing significant research on the International Space Station that could greatly benefit human health. Through advancing the state of scientific knowledge of our planet, looking after our health, and providing a space platform that inspires and educates health, science and technology leaders of tomorrow, these benefits will drive the legacy of the space station as its research enhances the quality of life here on Earth.

Ellen Stofan is the Chief Scientist for the National Aeronautics and Space Administration (NASA/Jay Westcott)NASA’s International Space Station Chief Scientist Julie Robinson, Ph.D. (NASA)

In today’s A Lab Aloft, International Space Station Chief Scientist Julie Robinson, Ph.D., looks at how research will ramp up with the advent of the commercial crew.

The International Space Station (ISS) represents a key milestone for NASA in exploration research for future missions, in economic development of low-Earth orbit (LEO), and in developing commercial research and development for the ISS National Laboratory. Each of these three areas depends on getting the maximum research knowledge out of the facilities and infrastructure that has been built.

Even though we try to minimize crew hands-on time when we design experiments, the unique things that can be done aboard station are highly dependent on the crew. Crew members serve as the eyes and ears of the scientists. They also serve as research subjects for the wide variety of investigations in physiology and behavioral health. In biology and physics, they do the delicate laboratory tasks that cannot be automated. Given this importance, it may not surprise you to learn that crew time for research is one of our most limited resources in the laboratory.

European Space Agency Astronaut Samantha Cristoforetti performs maintenance on a controller panel assembly in the International Space Station’s Tranquility module. Life aboard the space station is one of constant maintenance and working with science investigations. (NASA)

When we hit a limitation such as crew time, it means that facilities might sit unused waiting for crew to change supplies, or that fewer physiology experiments can be done. In other words, we aren’t getting the maximum amount of research that the station could be doing if it didn’t have this constraint. Fortunately, the station was designed to support seven crew members, and almost all the daily time of that extra crew member will be devoted to research when they can be safely housed aboard station.

Researchers are waiting patiently (well, actually impatiently) for Commercial Crew Program (CCP) spacecraft to fly so that the crew can be augmented, and research can gear up to a higher rate. CCP also includes special requirements for model organisms such as rodents or fruit flies, advancing live return and ground processing capabilities. Commercial crew is on our critical path to getting the most research out of the space station, whether to benefit future exploration, expand research in LEO after ISS is complete, and most importantly, to make our lives and health better back here on Earth.

Julie A. Robinson, Ph.D., is NASA’s International Space Station Chief Scientist, representing all space station research and scientific disciplines. Robinson provides recommendations regarding research on the space station to NASA Headquarters. Her background is interdisciplinary in the physical and biological sciences. Robinson’s professional experience includes research activities in a variety of fields, such as virology, analytical chemistry, genetics, statistics, field biology, and remote sensing. She has authored more than 50 scientific publications and earned a Bachelor of Science in Chemistry and a Bachelor of Science in Biology from Utah State University, as well as a Doctor of Philosophy in Ecology, Evolution and Conservation Biology from the University of Nevada Reno.

In today’s A Lab Aloft, guest blogger Liz Warren, Ph.D., looks at the differences between male and female astronaut physiology on long duration space missions.

I hate to break it to you, but men are not actually from Mars and women are not really from Venus. This silly saying illustrates a question that researchers, however, are serious about studying. With International Women’s Day around the corner, I thought it the ideal time to address the question: Is there a difference between the sexes as the human body adapts to microgravity?

Roscosmos cosmonaut Yelena Serova and ESA astronaut Samantha Cristoforetti live and work aboard the International Space Station as part of the current crew. (NASA)

In the fall of 2015, Sarah Brightman will be the 60th woman to fly in space. As we approach longer durations in human spaceflight, such as the one-year mission and the journey to Mars, it is important to tease out all aspects of how humans handle life in microgravity to ensure crew safety. The answers may also hold insights for human health even if you never leave the ground.

Our current crew aboard the space station includes ESA (European Space Agency) astronaut of Italian nationality, Samantha Cristoforetti, and a Roscosmos cosmonaut of Russian nationality, Yelena Serova. While serving aboard the orbiting laboratory for about six months, they each perform experiments in disciplines that range from technology development, physical sciences, human research, biology and biotechnology to Earth observations. This research helps in benefitting our lives here on Earth and enables future space exploration. They also engage students through educational activities in addition to operational tasks such as equipment maintenance and visiting vehicle tasks.

Russian cosmonaut Elena Serova, Expedition 41 flight engineer, works with hardware for the ОБР-8 Khimiya-Obrazovanie (Chemistry-Education) experiment in the Glove Minibox. Image was taken in the Rassvet Mini-Research Module 1 (MRM1) of the International Space Station. (NASA)

It’s important to acknowledge the contributions women in space make to both exploration and research. For instance, on Feb. 3, a prestigious tribute went to another woman space explorer, Japan Aerospace Exploration Agency (JAXA) astronaut Chiaki Mukai. She was conferred the National Order of the Legion of Honour, Chevalier. Mukai flew aboard space shuttle missions STS-65 and STS-95, and is currently the director of the JAXA Center for Applied Space Medicine and Human Research (J-CASMHR). The work these trailblazers accomplish also includes their role as research subjects themselves.

Female space explorers are skilled professionals, representing the best humanity has to offer, executing complex tasks in an unforgiving environment. Their sex differentiates them only so far as biology determines—which is exactly the topic covered in a recent compendium titled “Impact of Sex and Gender on Adaptation to Space.” The results were published in the November 2014 issue of the Journal of Women’s Health.

Samantha Cristoforetti taking images of the Earth from the International Space Station’s cupola. (NASA)

Space exploration is inherently dangerous, and as we look to longer duration spaceflights to Mars and beyond, NASA wants to make sure we are addressing the right questions to minimize risk to our astronaut crews. Based on a recommendation by the National Academy of Sciences, NASA and the National Space Biomedical Research Institute (NSBRI) assembled six scientific working groups to compile and summarize the current body of knowledge about the different ways that spaceflight affects the bodies of men and women. The groups focused on cardiovascular, immunological, sensorimotor, musculoskeletal, reproductive and behavioral implications on spaceflight adaptation for men and women. NASA and NSBRI created a diagram summarizing differences between men and women in cardiovascular, immunologic, sensorimotor, musculoskeletal, and behavioral adaptations to human spaceflight.

Thus far, the differences between the male and female adaptation to spaceflight are not significant. In other words, mission managers planning a trip to Mars, for example, can do so without consideration of the sex of the crew members. However, many questions remain unanswered and require further studies and more women subjects in the human-health investigations. There is an imbalance in data available for men and women, primarily due to fewer women having flown in space.

As a physiologist, I am intrigued by several of the differences described in the journal. An area that interests me in particular is cardiovascular physiology. According to the Centers for Disease Control and Prevention, cardiovascular disease—including heart disease, stroke and high blood pressure—is the number one killer of men and women across America. Many studies have shown that healthy habits including good nutrition and exercise are important for maintaining a healthy heart here on Earth. Those habits are even more important for astronauts on the space station.

Of the findings described in the journal, one is that women astronauts tend to suffer more orthostatic intolerance upon standing after return to Earth. Related to this finding, women also appear to lose more blood plasma during spaceflight. Possibly connected to the inherent differences in the cardiovascular system between men and women, male astronauts appear to suffer more vision impairment issues in space than women, although the difference is not statistically significant due to the small number of subjects—meaning more research needs to be done.

Another difference between men and women in spaceflight is worth noting, and that is the radiation standard. While the level of risk allowed for both men and women in space is the same, women have a lower threshold for space radiation exposure than men, according to our models.

This is an exciting time in human space exploration. We are addressing questions today that will lead to safer journeys off our planet. This month, NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko will embark on the first joint U.S.-Russian one-year mission to the space station. Most stays on station are six months in duration, but planners anticipate a journey to Mars to be closer to 1,000 days. This first one-year mission is a stepping stone in our travels beyond low-Earth orbit. NASA anticipates to continue one-year long missions, and women will be part of these crew selections.

In the meantime, what we learn about our bodies off the Earth has benefits for the Earth. In part one of this guest blog, I stated that, “in space exploration and in science, we stand on the shoulders of those who came before us.” I am thrilled to think of what we are about to learn from the one-year mission, as well as the continued research on and by both men and women in orbit. What an exciting time for humanity!

Liz Warren, Ph.D., communications strategist for the International Space Station Program Science Office. (NASA)

Liz Warren, Ph.D., is a physiologist with Barrios Technology, a NASA contractor supporting the International Space Station Program Science Office. Warren has a doctorate in molecular, cellular, and integrative physiology from the University of California at Davis, completed post-doctoral fellowships in molecular and cell biology and neuroscience, and has authored publications ranging from artificial gravity protocols to neuroscience to energy balance and metabolism.